Heat-Resistant Silicone Sleeves vs. Fiberglass: Which Is Best for Your Cables?

When protecting cables in high-temperature environments, two materials dominate: heat-resistant silicone sleeves and fiberglass sleeving. Both offer thermal protection, but their performance, cost, and application suitability differ significantly. This guide compares them head-to-head to help you choose the right solution.

Heat-resistant silicone sleeves are extruded from high-consistency silicone rubber with a continuous operating temperature of 180–200°C (peaks to 250°C). They’re flexible, waterproof, and provide excellent dielectric insulation (up to 1,000V). Ideal for automotive wiring, industrial sensors, and appliance harnesses, they resist oils, solvents, and UV light without cracking.

Fiberglass sleeving, coated with silicone or acrylic resin, handles higher temperatures—up to 650°C with silicone coating. It’s stiffer, non-waterproof unless sealed, and primarily used in ovens, furnaces, and heavy machinery where extreme heat is constant. However, it frays when cut and requires heat-shrink caps to prevent moisture ingress.

FeatureSilicone SleevesFiberglass SleevingMax Temp (Continuous)200°C550–650°CFlexibilityHigh (bends easily)Low (rigid)WaterproofYes (IP67+)No (unless coated)InsulationExcellentGood (coating dependent)CostModerateHigherInstallationSlide-on, no toolsCut + seal ends

For most modern applications—electric vehicles, LED lighting, robotics—silicone sleeves win due to ease of use and environmental resistance. They expand up to 200% for easy installation over connectors and contract snugly, eliminating the need for tape or ties.

In rare cases like steel mill proximity or turbine wiring, fiberglass remains the choice. But combining both—silicone over fiberglass—offers hybrid protection where needed.

Pro tip: Use braided silicone sleeves for added abrasion resistance in moving parts. Custom printing (e.g., voltage ratings) improves traceability.

Bottom line: Choose heat-resistant silicone sleeves for 90% of cable protection needs—flexibility, sealing, and longevity in one package.

Ready to upgrade your cable protection? Get a quote for custom heat-resistant silicone sleeves today.